The 3rd Generation Partnership Project (3GPP) is an organization that develops and maintains telecommunications standards for cellular communication networks, such as the Global System for Mobile Communications (GSM), Wideband Code Division Multiple Access (W-CDMA), Long Term Evolution (LTE), and more. In this application, a radio access network (RAN) portion of a 3GPP-based network is referred to as a “3GPP RAN.” Thus, a 3GPP RAN could include a GSM RAN, a LTE RAN, a W-CDMA RAN, etc. The 802.11 standards for Wi-Fi RANs are maintained by a separate organization, the Institute of Electrical and Electronics Engineers (IEEE).
Mobile traffic offloading is a term used to describe the use of complementary network technologies for delivering traffic originally targeted for cellular networks. The surge of mobile data traffic resulting from the increased usage of smartphones and tablets with both 3GPP and Wi-Fi capabilities, as well as the increase demands on audio and video streaming, and the explosion in Internet data access, especially the portion going through the mobile network, has increased the need for mobile data offloading. The main complementary network technologies used for mobile traffic offloading are Wi-Fi, femtocells, and Integrated Mobile Broadcast.
Although some known techniques exist for offloading from 3GPP RANs, these solutions either do not provide seamless interworking and handover between 3GPP and Wi-Fi RANs, require additional hardware, or require burdensome device configuration changes. One example prior art technique involves the use of Access Network Discovery and Selection Function (ANSDF) (see 3GPP TS 23.402 ANDSF), whose purpose is to assist user devices to discover access networks in their vicinity and to provide rules (policies) to prioritize and manage connections to all networks.
Another prior art technique uses Generic Access Network (GAN) offloading, which is based on 3GPP GAN standards (see 3GPP TS 43.318 and 3GPP TS 44.318) that are designed to extend mobile voice, data, and IP Multimedia Subsystem/Session Initiation Protocol (IMS/SIP) applications over Internet Protocol (IP) networks using Unlicensed Mobile Access (UMA) for external IP access into the wireless core network. With GAN, dual-mode User Equipment (UE) handset subscribers are provided seamless handover connections between 3GPP wireless LANs and 802.11 Wide Area Networks. A local network is based on private unlicensed spectrum technologies like 802.11/Wi-Fi, while a wide network is cellular 3GPP based services. On the cellular network, mobile handsets communicate over the air with a base station, to servers in the core network of the carrier. Under the GAN system, when a handset detects a wireless LAN, it establishes a secure IP connection through a gateway to a server called a GAN Controller (GANC) on the carrier's network. The GANC is presented to the mobile core network as a standard cellular base station. The handset communicates with the GANC over the secure connection using existing GSM/UMTS protocols. Thus, when a mobile handset moves from a GSM to an 802.11 network, it appears to the core network as if it is simply on a different base station.
Another prior art technique uses Inter Access Point Protocol (IEEE 802.11(f) IAPP). IEEE 802.11 (f) proposes a practice for the implementation of Wireless Distribution System Services, and a protocol which allows Wi-Fi Access Points (APs) from different vendors to communicate with each other in a standardized manner and interoperate together to enable Wi-Fi based wireless devices to move between different wireless regions served by different Wi-Fi vendors' applications. This standard has been dropped, and is not being pursued by service providers.
Another prior art technique offloads traffic to femtocells. This technique makes use of standard cellular radio technologies to enable UEs to participate in the data offloading process. However, this option requires some modification to the devices to accommodate the different backhaul connection, as well as the use of unlicensed spectrum. Given that cellular radio technologies are founded on the ability to do network planning within licensed spectrum, it has been deemed to be difficult, from both a technical and business standpoint, to mass deploy femtocell access points.
Some additional techniques include indoor offloading (which makes use of standard cellular radio technologies to enable UEs to participate in the data offloading process), and Wi-Fi hotspot offloading (which can offload between Wi-Fi networks).
Each of these prior art techniques is lacking in that they do not provide seamless interworking and handover between 3GPP based RANs using licensed spectrum and 802.11 or cellular (e.g., femtocell) based RANs that use unlicensed spectrum. Also, these solutions require new hardware, or considerable modification to current network hardware and UEs.